1. Field of the Invention
The present invention relates to terminal device and control program thereof for displaying display information in a display section capable of three-dimensional display.
2. Description of the Related Art
Conventionally, various techniques are used to three-dimensionally display (3D display) in a flat display section display information such as images (still images and moving images), text, and menus to enable users to stereoscopically view the display information. As a technique such as this, for example, a technique is known in which an object in two-dimensional (2D) display information can be viewed stereoscopically by a visual effect that makes the object appear three-dimensional being applied to the object.
A technique using a polygon is an example of this technique. A technique is also known that uses binocular disparity between the right eye and the left eye of the user. That is, in this technique, display information for the right eye and display information for the left eye that are slightly misaligned with each other are provided, and an electronic parallax barrier (switching liquid crystal panel) that blocks light paths is placed in an appropriate position such that, when these two display information are simultaneously shown, the display information for the right eye is visible to the right eye but not to the left eye, and the display information for the left eye is visible to the left eye but not to the right eye. As a result, the display information appears three-dimensional.
All 3D display techniques described above use a parameter referred to as 3D depth that indicates the depth of 3D or the extent of outward projection. The stronger the 3D depth the deeper or more outwardly projecting the display information appears to the user. On the other hand, the weaker the 3D depth the shallower or less outwardly projecting the display information appears. When the 3D depth is zero, the display information appears two-dimensional (in other words, 2D display).
A display system is conventionally known that uses an electronic parallax barrier to convert flat (2D)/three-dimensional (3D) images accordingly and display the converted images (refer to, for example, Japanese Patent Application Laid-Open (Kokai) Publication No. 2006-121553).
However, in the above-described conventional technology, there are problems in that, when the text contents such as text information are displayed in 3D, the strain on the eyes outweighs the original benefit of 3D display, and electrical power is needlessly consumed by the load of the 3D processing. These problems similarly apply to still image contents and moving image contents in addition to text contents, and there is a significant difference in the benefit of 3D display depending on the content to be displayed.